Interlocking multipurpose airtool

ABSTRACT

A multipurpose air tool (1) having a handle (2) to which a head (3) can be removably attached is disclosed. The head (3) has attached thereto various such tools as a face plate (4) and replaceable nozzles (5). The head (3) is interlocked to the handle (2) by a spigot (19) and bayonet connection (21, 23, 34). A safety interlock (16) prevents operation of the trigger (15) and valve (12) unless the head (3) is correctly positioned on the handle.

This invention relates to an interchangeable assembly between a handpiece and multi attachments, of which each attachment when attached tothe hand piece gives the invention a variety of purposes, such as oneattachment is a pressure purging device used to launch pellets forpurposes of purging or cleaning tubes, pipes, conduits and hoses,another attachment is the spool attachment which allows for theprojection of a cord attached to a pellet through pipes, tubes, conduitsor hoses.

BACKGROUND OF THE INVENTION

Contamination of hoses, tubes, pipes and conduits represents a majorproblem to industry as it directly causes major plant and machinerybreakdowns requiring extensive repairs at a cost which is impossible tomeasure. The smaller the internal diameter of the hose, tube or pipe,the greater is the potential for damage caused by the presence ofcontaminants due to the inability to effectively clean these smalldiameter tubes.

Thus a system which effectively removes contamination from tubes, pipes,conduits and hoses, arising from use, or from manufacture, cutting andfitting of new assemblies is required. It is evident that a method isrequired to overcome the problems caused by the extensive component andsystem malfunctions due to particles of contamination. The traditionalmethods such as using pull-throughs, bowing out the lines with air orflushing with oil, solvents or chemicals are inefficient. Frequentlythese methods involved substantial labour and material costs. Solventsand chemicals utilised in the process represented a hazard to the userand often created disposal problems, having regard to the toxicity ofthe chemicals with environmental concerns.

It is known that the complex task can be achieved by propelling a foampellet through a hose, pipe, conduit or tube to be cleaned. The pelletis slightly larger in external diameter than the internal diameter ofthe hose, pipe, conduit or tube and consequently the pellet expandsagainst the internal surface thereby eliminating the contaminants as itpasses through. irrespective of whether they are liquid or solid.

U.S. Pat. No. 4,974,277 of which David Wayne Caseila is the inventor,describes a hand held pneumatic gun which has a breech pivoted to thegun, that is a hinged face plate, that can be opened to allow the nozzlesize to be changed and the projectile inserted therein. That gun has noadequate safety mechanism, and is limited in its use to a small range ofdiameter hoses and pipes, and comprises of one assembly and does nothave the interlocking multi-purpose assembly. Application Ser. No.AU663294 (83338/91) Is an Improvement on U.S. Pat. No. 4,974,277 and hasthe exact same limitations.

It is the object of this invention to provide a multi-purpose pneumatictool having a multi function hand piece with interchangeable attachmentsor heads. One such attachment is the pressure purging which is easilyadapted to a wide range of internal diameters of pipes, tubes or hoses,and another is the spool head.

Also it is an object of the invention to provide a wide range of headswhich will be adapted to separate and different tasks but each will beinterchangeable with the interlocking assembly.

The multi function hand piece, by using an unique interlocking assembly,can be used for a variety of different purposes by the attachment ofdevices for cleaning for pipes, tubes and hoses, a spooling attachment,and other attachments such as a venturi system for sand blasting or theextraction of the addition of liquids to the air stream, an air drill,and pressure testing of pressure systems.

An additional object of the invention is to provide a safety device,both automatic and manual to prevent the operation of the hand pieceunless the attachment or head is correctly positioned and affixed by theinterlocking assembly between the multi function hand piece andattachment or head.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more fully describe the invention, reference will now bemade to the accompanying drawings in which:

FIG. 1 is a perspective view of the hand piece interlocked to thelauncher head,

FIG. 2 is a cross sectional view of one form of the invention,

FIG. 3 (a) shows a view of the handle with the head detached, and views(b), (c) and (d) each show a detached head and face plate of varyingsizes to accommodate various sized nozzles and thus projectiles.

FIG. 4 (a) shows a further form of head with face plate removed, thehead containing a fixed spool, while FIG. 4 (b) shows a free runningspool to replace the fixed spool,

FIG. 5 is a view of the face of the handle to which the head isattached, and shows the head part of the interlocking assembly.

FIGS. 6 (a) and (b) show examples of the head and face place withnozzles of differing sizes, and

FIG. 7 is a rear view of the head portion which contacts the handle andshows the head part of the interlocking assembly.

BRIEF DESCRIPTION OF THE INVENTION

There is provided according to the invention an interlockingmultipurpose air tool comprising a multi function handle, a connectionin the handle for the connection to a supply of compressed air, atrigger actuating a valve in the handle for controlling the flow ofcompressed air, characterised in that said air tool includes a head,interlocking means removably connecting said head to the said handle, anattachment connected to said head, said attachment connecting said airsupply to a point of use, and a safety lock between said head and saidhandle to prevent the operation of the trigger until the head iscorrectly positioned on said handle, whereby the said head can carry oneof a plurality of attachments depending on the use to which the airtoolis put.

Preferably the interlocking mechanism comprises a hollow spigot for thepassage of air therethrough interconnecting the said head and saidhandle, and a bayonet connection therebetween including a headed pin andarcuate slot, said arcuate slot having a radius of curvature centred onthe hollow spigot whereby relative rotation between the said head andsaid handle locks said pin in said arcuate slot.

Preferably also the head has a hinged face plate attached thereto, saidface plate having an aperture to receive one of a plurality of nozzlesfor launching pellets through a pipe, hose, tube or conduit.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring firstly to FIG. 1, there is shown a general arrangement of theinvention. The launcher 1 has two main components comprising a multifunction handle 2. and a head 3. In this example the head has pivotedthereto a face plate 4 with a nozzle 5.

The handle 2 has a connection 6 to which the compressed air supply maybe connected, the connection opening to a passage 7 connecting topassage 8 which is closed by a plug 9 at one end and closed by a valve11 having a valve stem 10, the valve having a sealing ring 12 engagingon a seat 13 formed in the handle. The valve 11 is biased to the closedposition by a spring 14. The valve stem 10 is engaged by a trigger 15.Preferably the valve 11 is designed such that the operator does not haveto hold the valve in the open position against the air pressure whichcan be 250 PSI or more. Thus the valve is designed as a pressure assistvalve or a balanced valve so that as equal air pressure is exerted onboth sides of the valve, the user thus only has to act against thespring pressure of spring 14.

The trigger 15 is pivoted to the handle 2 by pivot pin 41 and alsoengages the end of a safety lock 16. the operation of which will bedescribed in more detail later.

The valve 11 controls the flow of compressed air into passage 17 openingto passage 18 leading to the head 3. The head 3 has a hollow spigot 19with a through passage 42 which seals by sealing rings 20 into thepassage 18. The head 3 is detachable from the handle 2 and is retainedin position by a bayonet form of connection comprising an attaching pin21 attached to the face 22 of the head. As shown in FIG. 5 the end face43 of the handle has a recessed arcuate slot 32 extending from hole 33to receive the pin 21 and its enlarged end forming a head 23. Thearcuate slot has its radius of curvature extending from the centre lineof the spigot 19. The slot 32 has an arcuate opening 34 of lesser widththan the slot 32, the hole 33 having a diameter to receive the head 23and the arcuate opening 34 has a width to allow the pin to pass therealong, the head 23 being retained in the slot. To join the head 3 to thehandle, the spigot 19 is inserted in the passage 18. and the pin 21 andits head 23 in the hole 33. Rotation of the head 3 about the spigot 19relative to the handle 2 then securely locks the head 3 to the handle 2by the flange 23 engaging in the arcuate slot 32, the face 22 of thehead being in contact with the face 43 of the handle.

The safety lock 16 in the handle 2 is adapted to extend from the face 43of the handle when the trigger is actuated. However unless the head iscorrectly located in position the safety lock cannot protrude for itwill engage against the face of head 23. Thus this safety lock ensuresthat the head must be correctly positioned before the trigger can openthe valve to prevent the inadvertent operation of the valve, for the airpressure may cause the head to be thrown from the handle with greatforce if not secured in position.

The face plate 4 is hinged to the head 3 by hinge pins 24, and on theopposite side has a latch pin 25 to engage in a key lock 26 on the head3. The face plate 4 has an opening 44 to receive a nozzle 5 which inthis example has a cylindrical portion 27 tapering to a dischargeopening 28. At the other end the nozzle has a flared portion 29. Seatingrings 30 provided on the face plate engage the nozzle when the nozzle ispositioned in the face plate, and sealing rings 31 are also positionedon the head to seal against the nozzle when in use. Thus the nozzle issealed against the face plate and also against the head.

In use of this embodiment of the invention, to attach the nozzle, theface plate is opened by depressing key lock 26 thereby unlocking theface plate from the head so that it swings away from the head. Thenozzle is then inserted through the opening in the face plate and pushedso as to be seated on the sealing rings.

The cleaning pellet is then inserted into the nozzle, the face plate isclosed and the flange on the nozzle sealing against sealing rings on thehead.

In use the of this embodiment the nozzle is applied to the end of thehose, pipe or tube (to be cleaned of its contaminants) and held tightlyagainst the end of the hose, tube or pipe. A firm pressure is all thatis required. The trigger is then actuated and the air pressure forcesthe pellet through the hose. tube or pipe. The pellet will traversecurves and bends, even right angled elbow bends and also travel throughball and other straight-through valves. If the hose, tube or pipescomprise a number of branches and alternate routes, if all the routesare closed except the route to be cleaned, (which is opened toatmosphere) the pellet will follow that route to atmosphere. The pelletis preferably a compressible foam material and can be recovered at theend of the hose, tube or pipe.

To remove the head from handle. the manual locking pin lever 48 is movedrearwardly thus disengaging locking pin 16. The head 2 is then partiallyrotated to disengage the pin head 23 from arcuate groove in the handle,the head 2 then being moved axially to extract the spigot from thepassage in the handle.

As shown in the drawings the detachable head can be manufactured invarious sizes, for example, (a) 2 mm-32 mm range, (b) 32 mm-55 mm rangeand (c) 60 mm-80 mm range. For the oil industry the size could be up to150 mm. Thus each size of head can acconmmodate a range of nozzles, thenozzles having a flange to fit the head and tapering to the requireddiameter for the particular situation. Also In the range of nozzles, theend of the nozzle which is required to engage the end of the hose, tubeor pipe can be contoured appropriately depending on the shape fitting onthe end of the hose, tube or pipe, for example whether the end isflared, has a threaded end, or has a square end. Examples of the faceplate and nozzles are shown in FIGS 6a and 6b.

Where it is required that wires, cables or the like be threaded througha pipe tube or conduit, the invention also provides provision for theprojectile have attached thereto a line which is then drawn through thepipe tube or conduit by the pellet. Reference to FIG. 4a shows anexample of a head 3 which is formed with a cavity 36 having a spool 37on a shaft 38. The spool can contain a length of fine line or thread,the tree end of which is attached to the pellet. The face plate (notshown) is pivoted to the head as above described. The air flows throughthe passage 42 into the cavity 36 around the spool and through thenozzle attached to the face plate driving the pellet with the lineattached thereto through the tube or conduit.

FIG. 4a shows a rotatable spool with the line being fed through guidesas it is fed from the spool. The spool illustrated in FIG. 4a isrotatable and an adjustable brake 39 is provided to prevent over run ofthe spool when the pellet reaches the end of its travel. An adjustmentsuch as a nut 40 provides the required adjustment so that the brakingdoes not provide undue resistance to the travel of the pellet, but stillprevents over run of the spool. FIG. 4 (b) shows an example of a fixedspool without a brake, and the nut can be lightened to prevent rotation,or alternatively the spool can be mounted on the shaft by splines orthe, shaft having a flat with the bore in the spool having acomplimentary shape.

The handle has openings 46 and 47 which are closed by plugs but whichcan be connected to a pressure gauge, or a pressure relief valve, orother systems such as a venturi system.

While the above describes a multipurpose handle to which the heads ofthe pellet launchers can be attached, it is to be realised that otherheads can be part of other devices and units other than pelletlaunchers, Thus other devices such as line pressure testers, dusters,air drills and the like can be provided with heads as above describedand are adapted to be attached to the multipurpose handle. Thus the usermay only have one multipurpose handle and a range of heads forming partof the various devices.

Thus it will be seen that there is provided according to the invention amultipurpose handle forming an air tool, it is easily able toaccommodate for a wide range of hose, tube or pipe diameters, simply bychanging the nozzles, and also by using the appropriate sized head. Thesafety lock on the handle ensures that inadvertent operation of thetrigger while attaching the head is prevented.

Although various forms of the invention have been described in somedetail the invention is not to be limited thereto. but can includevariations and modifications falling within the spirit and scope of theinvention.

I claim:
 1. An interlocking multipurpose air tool comprising a multifunction handle, a connection in the handle for the connection to asupply of compressed air, a trigger actuating a valve in the handle forcontrolling the flow of compressed air, characterised in that said airtool includes a head, interlocking means removably connecting said headto the said handle, by relative rotation of the head to the handle, anattachment connected to said head, said attachment connecting said airsupply to a point of use, and a safety lock between said head and saidhandle to prevent the operation of the trigger until the head iscorrectly positioned on said handle, said safety lock engaging aposition of the head when not correctly positioned by the relativerotation of the head whereby the said head can carry one of a pluralityof attachments depending on the use to which the airtool is put.
 2. Anair tool as defined in claim 1 wherein the interlocking means comprisesa hollow spigot for the passage of air there through interconnecting thesaid head and said handle, and a bayonet connection there betweenincluding a headed pin and arcuate slot, said arcuate slot having aradius of curvature centred on the hollow spigot whereby relativerotation between the said head and said handle locks said pin in saidarcuate slot.
 3. An airtool as defined in claim 2 wherein the handle hasa face contacting said head, a passage opening to the face andcommunicating with said valve, a surface on said head to contact saidface on the handle and said hollow spigot extending from said surfaceadapted to sealingly engage in said passage whereby said head isconnected to the handle by insertion of the spigot into said passage andpartial rotation of the head relative to the handle to lock the head tothe handle.
 4. An airtool as defined in claim 3 wherein said headed pinextends from said surface, said pin being adapted to engage in saidarcuate slot in the face of said handle.
 5. An airtool as defined inclaim 4 wherein said arcuate slot has an opening at one end thereof toreceive said headed pin, said arcuate slot having edges extending fromsaid opening spaced to receive said pin whereby said edges prevent saidheaded pin from passing out of said slot.
 6. An airtool as defined inclaim 2 wherein said safety lock comprises a locking pin pivoted fromsaid trigger, said locking pin extending from the face of the handlewhen the head is correctly positioned on the handle and when saidtrigger is operated or when a manual locking pin lever is applied, andsaid locking pin engaging the said surface of the head when the head isnot correctly positioned thus preventing operation of the said trigger.7. An airtool as defined in claim 1 characterised in that one saidattachment is a pressure purging device to launch pellets to purge orclean a tubular member, said head having pivoted thereto a face plate toreplaceably receive a nozzle for the said pellet.
 8. An airtool asdefined in claim 7 wherein said face plate has a central passage toreceive said nozzle, said nozzle sealing on the face plate.
 9. A deviceas defined in claim 7 wherein said head has a recess to receive a spoolof line or thread, the free end of the line or thread connected to saidpellet, whereby on operation of the device the pellet will draw thethread through the tubular member.